﻿using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.Serialization.Json;
using System.Text;
using System.Threading.Tasks;

namespace Model
{
    /// <summary>
    /// Json辅助类
    /// </summary>
    public class JsonHelper
    {
        /// <summary>
        /// 序列化为JSON
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="obj"></param>
        /// <returns></returns>
        public static string Serialize<T>(T obj)
        {
            DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
            MemoryStream ms = new MemoryStream();
            serializer.WriteObject(ms, obj);
            string retVal = Encoding.UTF8.GetString(ms.ToArray());
            return retVal;
        }

        /// <summary>
        /// 反序列化为对象
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="json"></param>
        /// <returns></returns>
        public static T Deserialize<T>(string json)
        {
            if (string.IsNullOrWhiteSpace(json))
            { return default(T); }
            T obj = Activator.CreateInstance<T>();
            MemoryStream ms = new MemoryStream(Encoding.Unicode.GetBytes(json));
            DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
            obj = (T)serializer.ReadObject(ms);
            ms.Close();
            return obj;
        }
        #region json日期转换
        /// <summary>
        /// json日期转换
        /// </summary>
        /// <param name="value">json长整形日期</param>
        /// <returns>正常时间格式</returns>
        public static DateTime JsonToDateTime(string value)
        {
            value = value.Replace("/Date(", "").Replace(")/", "");
            DateTimeKind kind = DateTimeKind.Local;
            int index = value.IndexOf('+', 1);
            if (index == -1)
                index = value.IndexOf('-', 1);
            if (index != -1)
            {
                kind = DateTimeKind.Local;
                value = value.Substring(0, index);
            }
            long javaScriptTicks = long.Parse(value, System.Globalization.NumberStyles.Integer, System.Globalization.CultureInfo.InvariantCulture);
            long InitialJavaScriptDateTicks = (new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc)).Ticks;
            DateTime utcDateTime = new DateTime((javaScriptTicks * 10000) + InitialJavaScriptDateTicks, DateTimeKind.Utc);
            DateTime dateTime;
            switch (kind)
            {
                case DateTimeKind.Unspecified:
                    dateTime = DateTime.SpecifyKind(utcDateTime.ToLocalTime(), DateTimeKind.Unspecified);
                    break;
                case DateTimeKind.Local:
                    dateTime = utcDateTime.ToLocalTime();
                    break;
                default:
                    dateTime = utcDateTime;
                    break;
            }
            return dateTime;
        }
        #endregion
    }
}
